The present invention relates to lenses having a dual chromatic effect when viewed from the side opposed to the wearer.
The present invention relates to lenses, and, in particular, to lenses for use in sunglasses, which are externally treated in such a way to produce a new dual chromatic effect when viewed from the side opposed to the wearer. In particular, the present invention is directed at lenses that, when viewed from the side opposed to the wearer, reflect light in two different colors, one of which is reflected in a gradient manner.
In the prior art, chromatic effects have been generally achieved on lenses by depositing interference film on the outer surface of the lens. By choosing a film thickness properly, one can get a wide spectrum of reflected colors.
A common way to obtain a reflected color on the outer surface of a sunglass lens is to uniformly deposit a stack of dielectric films with alternative high and low refraction indexes. Such lenses are described in U.S. Pat. No. 3,679,291, which is hereby incorporated by reference.
Other chromatic lenses and methods for achieving the same are described in U.S. Pat. No. 4,160,584, which is hereby incorporated by reference. In one method, a uniform metallic layer is deposited over a substrate, and then a uniform dielectric material is deposited over the entire metallic layer. As described in U.S. Pat. No. 4,160,584, by depositing a thin transparent layer of a dielectric material on a thin transparent layer of metal, the light partially reflected changes its wavelength composition moving from the white light to a colored light of the spectrum depending on the thickness of the dielectric layer.
In a second method, also disclosed in U.S. Pat. No. 4,160,584, the metallic layer is gradiently deposited over the entire substrate and is then uniformly and entirely covered by a dielectric layer. In this case the outer surface will appear with a gradient colored reflection at the top becoming completely clear at the bottom.
In each of the two methods described above, the resultant lens produces a single, or single-gradient chromatic effect. That is, while colored, each of the lenses are of a single color. Various different materials for use in the metallic and dielectric layers, and the different colors that can be achieved, are described in U.S. Pat. No. 5,054,902, which is incorporated herein by reference.
The present invention is directed at providing a lens having a dual chromatic effect by utilizing at least one layer deposited in a gradient manner. The present invention is also directed at methods of manufacturing such lenses.
The present invention is directed to lenses, and, in particular, to lenses for use in sunglasses, treated in such a way to produce a new dual chromatic effect. In particular, the present invention is directed towards lenses comprising at least one layer deposited in a gradient manner, such that the lens has at least two zones with differently colored reflection. Even more particularly, the present invention is directed towards lenses comprising at least one layer deposited in a gradient manner, such that the lens has at least two zones with differently colored reflection, one of which is gradiently reflective.
In one aspect of the present invention, the lens comprises at least four layers including a substrate, a first dielectric layer comprising a high index dielectric material uniformly covering an outer surface of the substrate, a second dielectric layer comprising a first low index dielectric material uniformly covering the first dielectric layer, and a third dielectric layer comprising a second low index dielectric material gradiently covering only a portion of the second dielectric layer. The first and second low index dielectric materials can be the same or different materials.
In a second aspect of the present invention, the lens comprises at least four layers including a substrate, a metal layer comprising a metal material uniformly covering an outer surface of the substrate, a first dielectric layer comprising a first dielectric material uniformly covering the metal layer, and a second dielectric layer comprising a second dielectric material gradiently covering only a portion of the first dielectric layer. The first and second dielectric materials can be the same or different materials and can be either high or low index dielectric materials.
In a third aspect of the present invention, the lens comprises at least five layers including a substrate, a first metal layer comprising a first metal material uniformly covering an outer surface of the substrate, a first dielectric layer comprising a first dielectric material uniformly covering the first metal layer, a second metal layer comprising a second metal material gradiently covering only a portion of the first dielectric layer, and a second dielectric layer comprising a second dielectric material gradiently covering the second metal layer. The first and second dielectric materials can be the same or different materials and can be either high or low index dielectric materials, and the first and second metal materials can be the same or different materials.
In a fourth aspect of the present invention, the lens comprises at least five layers including a substrate, a first dielectric layer comprising a first dielectric material uniformly covering an outer surface of the substrate, a second dielectric layer comprising a second dielectric material uniformly covering the first dielectric layer, a metal layer gradiently covering only a portion of the second dielectric layer and a third dielectric layer comprising a third dielectric material gradiently covering the second metal layer. In a preferred embodiment, the first dielectric material is a high index dielectric material and the second and third dielectric materials can be the same or different materials and can be either high or low index dielectric materials.
Such lenses provide at least two zones with differently colored reflection when observed from the side of the lens opposed to the eyes of wearer. In particular, such lenses provide at least two zones with differently colored reflection when observed from the side of the lens opposed to the eyes of wearer, one of which is gradiently reflected.
Other objects and features of the present invention will become apparent from the following detailed description, considered in conjunction with the accompanying drawing figures. It is to be understood, however, that the drawings are designed solely for the purpose of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims.